Scraper sharpening apparatus

ABSTRACT

A kit for sharpening scrapers includes a burnisher, a block, a file and a clamp. The block has a plurality of bores for receiving the burnisher that are aligned at different angles relative to each other. The block is held in place by the clamp with the block below an upper surface of the clamp and the burnisher extending above the clamp. The block also includes a recess for holding the file during preparation of the scraper for sharpening. The scraper can have a linear or curved scraping edge.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 60/879,753 filed Jan. 10, 2007.

BACKGROUND OF THE INVENTION

The present invention is directed to an apparatus for sharpening scrapers of the type that are used in the finishing of woodwork and, especially for scrapers with linear or non linear scraping edges commonly known as cabinet scrapers.

Wood scrapers are tools that have been used by non commercial and commercial woodworkers for many years to finish wood surfaces of cabinets. Such scrapers are generally planar sheets of metal having at least one side where a scrapping edge is formed by biasing a side against a hardened material, especially at an angle, and forming a curl with a sharp edge. The edge extends outward and at varying angles from the plane of the scraper in accordance with the angle formed between the edge and the hardened material. The edge may be originally factory formed; however, the edge becomes nicked and/or loses sharpness with usage and must be sharpened. Therefore, woodworkers normally have a tool or set of tools for resharpening the edges of the scrapers.

When the edge is nicked, it is often best to start with a side having a squared side edge and then reform the entire side from it. Therefore, typically, the side of the scrapper is first filed or ground flat. This removes the old edge and restarts the edge forming process. The side edge is then passed along a hardened tool or burnisher that is held so that the side is at a selected angle relative to an axis of the burnisher. This causes the edge to turn and become sharpened. Additional passes may be made past the burnisher at increasing relative angles to vary the angle of the sharpened edge relative to the body of the scraper.

There are a number of prior tools designed to sharpen the blades. Such tools typically form an enclosed path for the body along with the edge to be sharpened to transverse a linear path past the hardened tool. This functions to sharpen linear edges, but does not work well with curved edges. Such devices are not able to sharpen curves that go inwardly or are concave in nature. The prior art sharpeners do not allow unobstructed access to the burnisher by the piece being worked. For example, one type of scraper takes on the shape similar to a french curve and has inwardly directed curves that can not be sharpened with traditional sharpening tools that require the edge being sharpened to travel along a linear path. Consequently, it is desirable to have a sharpening apparatus that is simple and works well for sharpening edges of all shapes, especially concave edges.

SUMMARY OF THE INVENTION

A sharpening apparatus for sharpening wood scrapers of the type used as cabinet scrapers. The apparatus includes a burnisher or hardened cylindrical shaped rod past which a scraper is driven or urged by a user of the apparatus to curl one edge of the scraper and form a sharp wood scraping sharpened edge therealong.

The apparatus further includes a block for holding the burnisher. The block has a plurality of cylindrical shaped openings or bores extending inwardly from at least one end thereof that snugly, but alternatively, slidingly receive the burnisher at the selection of the user. Each opening is drilled at a different angle relative to the other openings so as to provide a user with openings having different angles of inclination to receive the burnisher, so as to provide different sharpened curls depending on the need of the woodworker using the scraper. The block also preferably includes a recess for receiving a file or other grinding device to be held against the block on edge and allow a user to smooth or remove old sharpened edges to dress the edge or prepare for initially sharpening or resharpening the scraping edge.

The apparatus further preferably includes an abrasive media for initially filing or grinding the edge to a generally flat surface or, where curved to being generally linear from front to back and a clamping device or vise for holding the block in configurations for both preparing and sharpening the scraper. The abrasive media can include files of different types, sandstone, sand paper, diamond stone, oil wetstone and Japanese water stones. The clamping device has an upper surface and secures the block below the upper surface. The burnisher extends above the clamping device and is horizontally free of surrounding obstructions, so that the scraper being worked can move about the burnisher in an unobstructed manner in a horizontal or other working plane. Because of this, the scraper can be laid on the clamping device surface and the edge worked against the burnisher so as to sharpen the edge with the burnisher at a fixed angle dependent upon the opening used to receive the burnisher. Because the sharpener is not obstructed horizontally, the edge being sharpened can be curved and, especially can be concave, such that the scraper passes at least partly around the burnisher when concave regions of the edge are being sharpened. The person sharpening the scraper moves the scraper relative to the burnisher and maintains a radius of the burnisher in line with a radius of the curve of the edge being sharpened. Thus, the sharpener can sharpen scrapers of almost any shape.

OBJECTS AND ADVANTAGES OF THE INVENTION

Therefore, the objects of the invention are: to provide a sharpening kit for carpentry wood scrapers, including a burnisher, a block with variously aligned openings for slidingly receiving the burnisher and holding the rod at various selected angles relative to vertical, a file and a clamp; to provide such a kit wherein the burnisher is accessible to sharpen both linear edged scrapers and scrapers having curved edges, especially those having concave scraping edges; to provide such a kit that allows a user to both prepare or dress the scraper edge and then reshape and sharpen the edge for use in scraping wood; to provide such a kit that is easy to use, comparatively inexpensive to produce and especially well adapted for the intended usage thereof.

Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.

The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a burnisher holding block utilized in the invention.

FIG. 2 is a top plan view of the block.

FIG. 3 is a cross sectional view of the block taken along line 3-3 of FIG. 2, with a burnisher positioned in the block.

FIG. 4 is a cross sectional view of the block, taken along line 4-4 of FIG. 2.

FIG. 5 is a perspective view of the block, along with a file and a clamp, showing a scraper edge being prepared for sharpening.

FIG. 6 is a perspective view of the block, burnisher and clamp being used to sharpen a linear edged scraper.

FIG. 7 is a perspective view of the block, burnisher and clamp being used to sharpen a scraper having curved edges.

DETAILED DESCRIPTION OF THE INVENTION

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.

In accordance with the present invention, a kit is provided that is generally included by the reference numeral 1. The kit 1 includes a block 5 and a rod or burnisher 6. In some instances the kit also includes a file 7 and a vice or clamp 8. The kit 1 is utilized to sharpen scrapers 10 and 11.

The block 5, as best seen in FIGS. 1 to 4 is generally rectangular in shape having a top 15 and a bottom 16 that are both generally planar. The block 5 also has three generally planar side walls 19, 20 and 21 that are perpendicular relative to each other and the top 15 and bottom 16. A fourth wall 23 has a recess 24 located along one side thereof. The recess 24 is sized and shaped to receive the file 7. A corner 30 whereat the recess 24 joins with the side 23 is relieved to allow a sharpened edge to slide therealong without damaging the block 5.

Located in the top 15 and at least partially penetrating the block 5 along the length thereof between the top 15 and bottom 16 are a plurality of burnisher receiving openings 30, 31, 32 or 33. When the burnisher 6 is received in a selected one of the openings 30, 31, 32 or 33, the burnisher 6 partly extends upwardly and outwardly therefrom, such as is seen in FIG. 3.

Each of the openings 30, 31, 32 and 33 is cylindrical in shape and has an axis of rotation that is aligned such that each axis A, B, C and D respectively is at a different angle relative to each other and to the top 15. The angle of each opening 30, 31, 32 and 33 can be varied, but preferably such are aligned such that there is 0, 5, 10 and 15 degrees between a line perpendicular to the top 15 and the axes A, B, C and D, respectfully. The block 5 is constructed of aluminum, magnesium, a high impact polymer plastic such as high density polyethylene or other suitable material.

The burnisher 6 is a cylindrical rod that is constructed of hardened steel or the like that has a hardness that is substantially greater than the scrapers 10 or 11 to be worked by the kit 1. While the burnisher 6 is illustrated as being comparatively short, longer burnishers can be used with or without handles. As noted above, the burnisher 6 is sized to be held snugly in a selected opening 30, 31, 32 or 33.

The file 7 is a flat surfaced file that is also constructed of a metal that is harder than the scrapers 10 and 11. The file 7 is used in conjunction with the block 5 in a first preparation configuration, as seen in FIG. 5. In the preparation configuration, the block 5 is securely held in a rotated alignment by the clamp 8, so that the recess 24 is horizontally positioned and snugly receives the file 7 therein, so as to hold the file 7 in a fixed position. The recess 24 is positioned to extend over the clamp 8. The scraper 10 is shown in FIG. 5, with a linear scraping edge 40 engaging the file 7 and a first side 41 the scraper 10 abutting against the block top 15. The scraper 10 is moved back and forth along the file 7 as indicated by the arrow 44 in this configuration to remove an old sharpened edge 40 that has nicks or is otherwise damaged so as to prepare for forming a new sharpened edge 40. During sharpening a curl 45 that is sharp is formed along the edge 40. It is foreseen that the many different types of abrasive material may be used to dress the edge of the scraper to prepare it for sharpening which include, but are not limited to sandstone, sand paper, diamond stone, oil wetstone and Japanese water stone.

The clamp 8 has two spaced parallel bars 60 and 61, the spacing between which is controlled by a screw 62 with a turn handle 63. The bars 60 and 61 have upper surfaces 64 and 65 respectfully that are generally planar and horizontal so as to form a discontinuous surface 67 of the coplanar surfaces 64 and 65.

Shown in FIG. 6 is the scraper 10 being sharpened with the kit 1 in a second sharpening configuration. In this configuration, the block 5 is securely held in a fixed position by the clamp 8 below the clamp surface 67, such that the burnisher 6 extends vertically or above the surface 67 with no horizontal obstructions around the part of the burnisher 6 above the surface 67. The scraper 10 is then laid with side 41 facing upward, as is seen in phantom in FIG. 3. The scraper 10 is then moved in the direction shown by the arrow 70 back and forth under pressure against the burnisher 6, so as to curl back the upper part of the edge 40 to form the curl 45 which is sharp and is then utilized for scraping wood. The angle of the cutting curl 45 of the edge 40 can be varied by placing the burnisher 6 in the various openings 31, 32, 33 and 34.

It is foreseen that many types of clamps 8 can be used in accordance with the invention, including carpentry gluing clamps, vices and the like. As most carpentry shops have such, the clamp 8 is not provided with all kits and the file 7 may also be preexisting and not sold with the kit.

Seen in FIG. 7 in the kit 1 being utilized in sharpening the scraper 11 that has a non linear and concave scraping edge 80. When used to sharpen a curved edge, such as edge 80, the radius of the curve at any location therealong is maintained to be coaxial with the radius of the burnisher 6 while moving therealong and biasing the scraper 11 against the burnisher 6, so that a uniform curl is produced on the edge 80.

It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown. 

1. A scraper sharpener comprising: a) a block sized and shaped to be held in a clamp and having a top and a plurality of openings extending through said top and at least partly through said block; b) each of said openings being sized and shaped to snugly, but slidingly hold a burnisher and each having an axis; c) said opening axes each being aligned at a different angle relative to said top and to each other.
 2. The sharpener according to claim 1 wherein: a) there are first, second, third and fourth openings and said axes are aligned at 0, 5, 10 and 15 degrees respectively to a line perpendicular with respect to the top.
 3. The sharpener according to claim 1 wherein: a) said block includes a recess along one side thereof that is sized and shaped to receive a file.
 4. The sharpener according to claim 1 including: a) the burnisher.
 5. The sharpener according to claim 4 including: a) an abrasive material for dressing a scraper edge prior to sharpening; and b) the clamp sized and shaped to hold said block in a fixed position below an upper surface of said clamp, such that said burnisher, when received in any selected opening, extends above said clamp surface.
 6. A kit for sharpening scrapers comprising: a) a block having a top and side walls with a plurality of openings opening onto said top and extending at least partly through a length of said block; each of said openings being cylindrically shaped and having an axis; each of said axes being aligned at a different angle relative to each other; said block including a side recess; b) a burnisher sized and shaped to be snugly but slidingly received in each of said openings and extend above said top; said burnisher being hardened and adapted to receive a scraper edge for sharpening; c) a file sized and shaped to be received in said recess for preparing a scraper surface for sharpening; and d) a clamp for operably securing said block in a first position to allow use of the file to prepare an edge for sharpening and a second position for sharpening; said clamp having at least one upper surface adapted for receiving a side of the scraper during sharpening.
 7. A method of sharpening a scraper, including the steps of: a) providing a burnisher of harder material than the scraper; b) providing a block for holding the burnisher; said block including a plurality of openings with each opening aligned at a different angle relative to a top surface of the block compared to each other opening; c) placing the burnisher in a selected one of said openings that is selected to produce a desired sharpened curl on the scraper; and d) urging the scraper past the burnisher while maintaining one side of the scraper on a flat surface so as to produce the curl.
 8. The method according to claim 7 wherein: a) the scraper includes at least one linear edge to be sharpened.
 9. The method according to claim 7 wherein: a) the scraper includes at least one concave edge to be sharpened.
 10. The method according to claim 7 including the steps of: a) providing the block with a recess; b) placing a file in the recess; and c) preparing an edge of the scraper for sharpening by passing the edge over the file prior to sharpening. 